Telltale for motor vehicle lights



Nov. 14, 1933. G. H. INMAN 3 99 TELLTALE FOR MOTOR VEHICLE LIGHTS,

Filed June 12, 1930 iiigi igi aiiai gisi Patented Nov. 14, 1933 STATES- PATENT OFFICE This invention relates to indicating devices for automobiles, for the purpose of signaling or indicating to the operator of the same when any one of the lights upon the machine has burned out.

The primary object of the present invention is to provide a simple and novel type of indicator adapted to be placed in the circuit in series with the lights of the motor vehicle and remain inactive so long as the full amount of current necessary to energize all of the lights is flowing from the battery through the circuits.

. The invention broadly contemplates the provision of a solenoid having two coils,'.one of which 5 is in series in the circuit in which the motor vehicle headlights are placed while the other one is in series with the circuit in which the motor vehicle tail light is placed. These coils operate to maintain a metal core in a fixed position so .long as the full amount of current is flowing through both to the lights of the vehicle, As soon as any one of the lights of the vehicle burns out so that there is a drop in the amount of current flowing through either coil the core of the solenoid will be released and will then operate to close a circuit in which a telltale light is placed. The 'device is designed to be positioned under the instrument board of the motor vehicle so that when the telltale light becomes energized the area under the instrument board will be lighted up and will be immediately seen by the vehicle operator.

The invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawing forming part of this specification, with the understanding, however, that the invention is not confined to any strict conformity with the showing of the drawing but may be changed or 40 modified so long as such changes or modifications mark no material departure from the salient features of the invention as expressed in the appended claims.

In the drawing:

Figure 1 is a view in longitudinal section of the device embodying the present invention showing the same connected to the lighting circuit of a motor vehicle.

Figure 2 is a sectional view taken on the line 2-2 of Figure 1.

Figure 3 is a sectional view taken on the line 33 of Figure 1.

Figure 4 is a sectional View taken on the line 4-4 of Figure 1.

Figure 5 shows a modification which may be made to the lower part of the solenoid housing to facilitate the placing of .the telltale light at a point in the vehicle remote from the casing.

Referring more particularly to the drawing wherein like numerals of reference indicate corresponding parts throughout the several views, the device embodying the present invention is indicated generally by the numeral 1. This device comprises a metal casing 2 preferably of cylindrical design.

Inserted in one end of the casing is a sleeve 3 in which is formed at diametrically opposite points in the inner face thereof the grooves 4 and in a vertical plane at right angles to the plane in which the slots 4 are formed there is formed in the top edge of this sleeve the oppositely positioned notches 5. i

Into the sleeve 3 there is inserted the base portion of an incandescent lamp 6, the usual oppositely disposed pins thereof being passed through the slots 4 to the inner edge of the sleeve after which the lamp is given a quarter turn so that these pins will be brought into the position where they may enter the notches of recesses 5. The cylinder or casing 2 is secured in upright position preferably upon the forward face of the panel of the motor vehicle which separates the front foot space from the engine, by a supporting strip or band 7. This band partially surrounds the casing as shown and has its ends secured to the supporting panel (not shown) by screws or any other suitable means. I

In the end of the casing 2 opposite that in which the lamp 6 is mounted there is fixed a block of insulation 8 which carries four binding posts which are indicated by the numerals 9, 10, 11 and 12. These binding posts as shown extend through the'insulation body 8 to the interior of the casing.

Mounted within the casing 2 is a solenoid indicated generally by the numeral 13. This solenoid is made up of two coils both of which are wound thereon in the same direction so that the magnetic fiuxset up by one when a current is passed therethrough will coincide in the direction of flow with the fiow of the magnetic flux created in the other coil when a current is passed through it.

The terminals of one coil are indicated by the numerals 14. and 15 and as shown the terminal 14is connected with the binding post 12 while the terminal 15 is connected with the binding post 11. The terminals of the other coil are indicated by the numerals 16 and 17 and the terminal 16 is connected to the binding post 10 while 110 the terminal 17 is connected to the binding post 9, as shown.

The coil which has its terminals 16 and 1'! connected with the binding posts 9 and 10 con- Q sists of alarger number of turns of small wire than the number of turns of wire upon the coil which has its terminals 14 and 15 connected with the posts 11 and 12 and which is made up of a larger wire.

The coils of the solenoids are wrapped upon a metal cylinder 18 but are insulated'therefrom. Within the cylinder 18 the core 19 is mounted for reciprocation and as shown the solenoid is so mounted in the casing 2 that the core 19 when 15 allowed to drop through the action of gravity after de-energization of the coils, will come into contact with the center contact 20 of the telltale light .6. An electrical connection is made as indicated at 21 between the terminal 16' of the second mentioned coil and the metal cylinder in which the core 19 moves and the casing 2is connected with the grounded side of the motor vehicle battery 22 by the wire 23.

When the device is installed in the motor vehicle the negative side of the battery 22 is connected through the medium of the wire 24 with the binding post 12. The binding post 11 has connected thereto one end of the wire 25 which feeds current to the headlights 26, the usual headlight control switch, which is indicated by the numeral 27, being interposed in this sideof the circuit between the device 1 and the headlights.

An electrical connection is made through the 5,,.wire 28 between the binding post 10 and the wire 25, the connection being made with the wire 25 at a point between the switch 27 and the headlights 26 and the binding post 9 is connected by the wire 29 with the machine tail light 30.

In operation when the switch 27 of the car lighting system is closed current will flow from the battery through the wire 24 and through the coil to which it is connected, to energize, the headlights and also to energize the tail light by flowing through the wire 28 and the coil to which it is connected and then to the tail light by way of the wire 29, This flow of current through the two coils of the solenoid will be sufilcient to draw in the core 19 and; thus remove it from contact with the center contact of the telltale light 6. As the number of turns of the coils and the current going through the same .control the action of the solenoid it will be seen that for the tail light current to efiect the solenoid in anywhere near the same proportion as the headlight current, which is flowing in greater quantity than the tail light current, it is necessary 'for the tail light current to pass through more turns if its fiow is to do its share in holding up the solenoid core when the current is flowing to the tail light ,and weaken said solenoid enough when the tail light goes out to let the plunger down to meet the contact. When the tail light goes out the tail light coil goes deadand there also is a weakening in the main coil and both together weaken the solenoid to the extent that the plunger drops and makes a contact which lights up the telltale lamp. With only one coil the differences when the tail light goes out would be so small that it would not operate "accurately, if at all, as the voltage varies for one thing and the current is too slight to have any eiiect on the small number of lines that are necessary to take care of the headlight'current. Since .the headlight lamps each take approximately three times the amount a relatively large coil of large wire and a few of current required to operate the tail light it will be seen that a separate coil is necessary for the tail light circuit which is so formed that'the efiect of the current passing therethrough upon the core 19 will be relatively great and, therefore, create a decided weakening in the efiect of the electro-magnet when the tail light circuit becomes' dead. The use of a single coil for all of the lights would be ineffective for the reason that turns would be necessary and the small decrease in the amount of current flowing therethrough when the tail light became inoperative would hardly create a noticeable difieren'ce in the effect of the coil upon the core. Should any one of the vehicle lights burn out there will be a slight drop in the amount of current passing from the battery through one of the coils of the solenoid and this drop in current flow will sufiiciently weaken the solenoid to allow the core 19 to drop. As explained above, by the use of the two separate coils, the desired weakening of the solenoid will be obtained when either a headlight or the tail light burns out so as to release the core 19.

As soon as the core 19 comes into contact with '100 the center contact 20 of the light 6 a circuit will be established through the telltale light to energize the same and thus indicate to the operator of the motor vehicle upon which the device is mounted that one or more of the lights of the 1105 machine are out of operation. I

In the usual motor vehicle when the main light switch is turned on the first point lights the tail light only.

When this occurs it will be seen that all of the current drawn by the tail light is passing throughboth coils, that is the coil to which the headlights are attached and the coil to which; the tail light is attached, but the total amount of current flowing through these coils is insufllcient to lift the armature or solenoid coil 19 so that until the switch is thrown over to the next contact which will light up both the headlights and the tail light, the core will remain in contact with the telltale light 6 and this light will be energized. It will thus be obvious that when the device is used in association with a switch of this character, that is where the first point on the switch lights only the taillight and the second point lights both the headlights and the tail light it will be apparent to the operator of the machine, each time the lights are turned on, that the tell-' tale light is in operating condition.

If one of the headlights goes out, or the tail light, the current in the solenoid diminishes until there is not strength enough to hold up the armature, as a result of which the armature drops and makes contact with the center point of the telltale light, lighting the same. In this manner, the driver knows immediately that he has light trouble and as soon as the same is fixed enough current will again pass through the solenoid coils to lift the armatureand put out the tell-tale light.

In.Figure 5 there is shown a slight modification in the construction of the lower end of the cas-.- ing 1' which houses the solenoid. In this modified form the casing is indicated by the numeral la and in place of the lamp base it has fixed therein a body of insulation 31 which carries a contact button upon its inner face'as indicated at 32 which is connected with a wire 33. This wire may run to the telltale lamp here indicated by the numeral 34, which may be positioned upon the vehicle dash or at any other place therein.

. 1,935,399 It will be seen that when the telltale light a4 01 this modified construction is illuminated the core 19a of the solenoid will rest upon the button or contact 32 instead of uponthe center contact of the lamp base as itis shown in Figure 1.

Having thus described my invention, what I claim is: I

1. A telltale for the head and taillights of a motor-vehicle lighting circuit which includes a in series with the vehicle headlight circuit belas tween the switch controlling the circuit and the source 01' electrical energy therefor, the other of said coils being connected in series in the tan light circuit, said tail light circuit receiving its current'supply from the headlight circuit between the headlights and the control switch therefor, a telltale light, and a circuit therefor,

said core being in the telltale light circuit and operating upon movement in one direction upon diminishment of the current flow through said coils, to close the telltale light circuit to energize said telltale light, said coils having a combined strength, when the two headlights and the tail light are burning, sufllcient only to retain the core in a position to retain the telltale light circuit open. n

2. The combination with a motor vehicle lighting system including a pair of headlights and a tail lightya switch, and a source of electrical energy; of a solenoid disposed vertically and having aTdouble coil and a shiftable core, a light element positioned beneath the core of the solenoid and having a central contact disposed for engagement by the core when the same moves downwardly, the other contact of the light being electrically connected with the battery, four terminal members each being connected with one I end ofa coil, an electrical connection between said battery and one end of one coil, an electrical connection between the other end or the last mentioned coil and said headlights, said switch being interposed in said connection, an electrical connection between one end of the other coil and the connection to said headlights, and an elec- "trical connection between said tail light and the otherend. of said other coil, said last mentioned coil being electrically connected with the core of said solenoid. 1 r

3. A telltale {or the head and tail lights of a motor vehicle lighting system which includes a circuit having a source of electric potential and headlight lamps therein and a tail light circuit having a tail light lamp therein, a switch in said first circuit, said tail light circuit being connected in the headlight circuit between the switch and the first mentioned lamps, a solenoid comprising two coils encircling a'movable' core, oneof said coils being in series in the headlight circuit, the other of said coils being in series in the tail light circuit, a telltale light, a circuit having the telltale light and said core therein, and a contact in the last mentioned circuit, said core being normally held against the action of gravity, in

one position. in the coils and in spaced relation to said contact, by the combined strength of the coils through which current flowa when all ofthe lamps are energized, the burning out of 'one vof said lamps diminishing the current flow GILBERT HIRAM INMAN. 

